In this paper management strategies optimizing irrigation and also reducing the risk of secondary salinization were explored for seven Sicilian soil profiles by using the SWAP model. Two viable options addressing constraints of limited water availability were simulated for the seven soil profiles. These options were (i) different irrigation scheduling, i.e. irrigation with a fixed amount of water but different number of irrigations and (ii) cyclic strategies, i.e. alternating two irrigation waters having different salinity. Analysis of three different irrigation scheduling evidenced that making a limited number of irrigations (two in our case), using larger application volumes, determined a lower risk of salinization. With reference to the role of cracks in the process of salt-leaching, the simulations performed indicated that water stored in cracks promoted leaching of the accumulated solutes and that neglecting the presence of cracks led to overestimating salinization. Cyclic proved to be the best management option to be suggested to reduce the risk of salinization. Findings concerning the role of cracks in the process of salt-leaching suggested that, under field conditions, application of a leaching solution was more efficient if the soil presented a considerable degree of cracking.

Ce travail explore deux options différentes de gestion de l'irrigation qui peuvent concourir à la réduction du risque de salinisation en appliquant le modèle SWAP à sept profils de sol en Sicile. L'une consiste à irriguer selon trois calendriers différents et l'autre à alterner deux niveaux de salinité de l'eau d'irrigation. L'analyse de la première option montre que limiter à deux le nombre d'irrigations, en appliquant de grands volumes d'eau, diminue le risque de salinisation. Nos simulations prennent également en compte le rôle des fissures dans le processus de lessivage des sols afin d'améliorer les prévisions de salinisation. L'alternance de différents niveaux de salinité de l'eau d'irrigation semble être la pratique la plus efficace pour prévenir la salinisation du sol. Enfin, des résultats concernant le rôle des fissures dans le processus de lixiviation, suggèrent que, dans certaines conditions, l'application d'une solution de lessivage serait plus efficace si le sol présentait un degré important de fissures.